In a large bowl, whisk together the flour, baking powder, baking soda, and salt.
In another bowl, mix the milk, egg, sugar, and melted butter or oil.
Gradually add the wet ingredients to the dry ingredients, stirring until just combined. The batter should be smooth but slightly thick.
Heat a non-stick skillet or griddle over medium heat and lightly grease it if needed.
Pour a small amount of batter onto the skillet to form pancakes, about 3 inches in diameter. Cook until bubbles form on the surface and the edges look set, then flip and cook until golden brown on the other side. Repeat with the remaining batter.
In a bowl, combine the chopped walnuts, sugar, ground cinnamon, and honey or date syrup. Mix well. If desired, melt the butter and stir it into the mixture.
Place a spoonful of the filling onto the center of each pancake while it is still warm.
Fold the pancake in half and press the edges to seal, forming a half-moon shape. You can lightly pinch the edges together to ensure they are sealed.
Arrange the filled Atayef on a serving plate. Dust with powdered sugar and drizzle with extra honey or date syrup if desired.
Enjoy your meal!